In 1970 approximately 50 such churches existed, growing to 150 by 1980, 310 in 1990 and at least 600 by 2000. The number doubled to 1210 by 2005. This rapid growth has slowed slightly with an estimate of over 1350 US megachurches currently. This dramatic increase surprised researchers and confirmed their hunch that the movement is not only popular, but spreading rapidly.

People have said, “This is a baby-boom phenomenon. The megachurches reached their apex and are waning,” said Scott Thumma of the Hartford Institute for Religion Research, the lead researcher. “I never believed that. But I did underestimate how rapidly the phenomenon was spreading.”

In addition to the growing numbers of megachurches, the study found individual congregations grew quite rapidly. The average weekly attendance at megachurches rose to 3,585 in 2005 and 4142 in 2008, compared to average attendance of 2,279 people megachurches reported in 2000. These studies found that the more recently a megachurch was founded, the more rapidly it was growing and the larger the average size of the worship attendance. This may indicate that these recently founded churches are born with a large church model in mind and are taking advantage of the lessons of older megachurches, borrowing their strategies to boost attendance. Click here for more specifics about the megachurch research.

Although megachurches still account for less than half of 1 percent of all congregations in the United States, they are drawing an increasing share of members, estimated at 7 to 10 percent of all Protestant worshippers on any given week. A searchable database of megachurches is available here.

“If all megachurches together formed one denomination,” said Warren Bird, director of research at the Leadership Network, “they would be the fifth-largest Protestant body.”

In nearly all megachurches the senior pastor is a main attraction and is one of the primary draws for new members. Nearly all megachurches use electric guitars and drums, as well as visual projection equipment. Ninety percent of megachurches described their services as spiritually alive, joyful, inspirational, and thought-provoking.

“Whatever they’re doing in worship, it is clearly resonating with a lot of contemporary folks,” said Thumma. “This is what many people want in terms of the presentation of the Gospel.”

Megachurches share other characteristics. Between 35 and 40 percent of these churches are non-denominational. Many others minimize their denominational ties, most obviously by dropping the affiliation from the church’s name. Theologically, 65 percent of the churches chose the designation "Evangelical" and another 11 percent "Pentecostal or Charismatic." Politically, 33 percent of respondents identified themselves as predominantly conservative, and another 44 percent said they were somewhat conservative.

Still, the researchers caution that not all megachurches are alike. Older megachurches do not look like newer ones and larger ones function differently than smaller one. Likewise, the race of the pastor makes some difference as does the theological orientation of the church. Therefore, like with every shifting terrain, the mapping of this phenomenon must continue.